The original first-generation dials (Type 1) are characterized by the typical “pie-pan” dial design which was common for most other Day-Date dials of this period. The minute track slopes down like an upside-down ‘pie-pan’. The glossy look of the Type 1 (and also the Type 2 dials) is further enhanced by the Plexiglas “Cy-clope 136” crystal that Rolex fitted at the time.
Following the Type 1 dials of early 1970s (please take note that there is an overlapping period of all the dials and no clear cut off point) one can find the Type 2 dial, which doesn’t have the “pie-pan” design but is still marked T Swiss T. On these watches you’ll find different text colors (not only black lettering as seen on the Type 1 dial). They used gold lettering for yellow gold models and silver text for white metal watches.
The Type 3 dial marked “T Swiss Made T” with a flat dial design one can find predominantly in the single quick set Ref. 180xx of the later 1970s and early 1980.
The “final” evolution Type 4 dial was manufactured until the end of the 1980s and featured a Roman Nu-meral outer ring. Interestingly we can find several watches with Stella dials until the late 1990s. Most are fitted in platinum Day-Dates. Whether these last dials were left over spare dials owned by certain dealers or a late series by Rolex, remains unclear.